Search Results

You are looking at 21 - 30 of 3,998 items for :

  • Lidar observations x
  • All content x
Clear All
Florian Pantillon, Bianca Adler, Ulrich Corsmeier, Peter Knippertz, Andreas Wieser, and Akio Hansen

models. Several cases were sampled with a Doppler lidar during the Wind and Storms Experiment (WASTEX) that took place in winter 2016–17 on a former waste deposit topping at 50-m height and located in the Upper Rhine Valley near Karlsruhe in southwestern Germany ( Pantillon et al. 2018b ). Doppler lidar measurements are challenging in extratropical cyclones due to the low aerosol load, which hinders observations after the passage of fronts. This was the case during the extreme windstorm “Egon” on 12

Open access
Stephan F. J. De Wekker and Shane D. Mayor

proven very useful in the understanding of atmospheric dynamics and structure. Shortly after the development of the first pulsed lasers, the applicability of lidar to the study of mountain-wave-related phenomena was recognized. Collis et al. (1968) were the first to document aerosol lidar observations in the Sierra Nevada in February and March 1967, followed by more comprehensive observations by Viezee et al. (1973) in March and April 1969 and 1970. These studies provided evidence that pulsed

Full access
Bianca Adler, Olga Kiseleva, Norbert Kalthoff, and Andreas Wieser

correlated), and the spectral peak wavelength λ m (as the size of the eddies with the most energy). Reliable measurement of these parameters is crucial for the understanding of the CBL structure and evolution. Variance profiles can be derived from aircraft observations using spatial averages (e.g., Lenschow and Stephens 1980 ; Lenschow 1986 ; Young 1988 ; Grunwald et al. 1998 ) and from tower or wind lidar measurements using temporal averages (e.g., Neff 1990 ; Grund et al. 2001 ; Emeis 2011

Full access
A. Protat, J. Delanoë, E. J. O’Connor, and T. S. L’Ecuyer

troposphere and preferential regions of high cloud occurrence, tropical ice clouds are of particular importance, owing to their extensive horizontal and vertical coverage and long lifetime (e.g., Sassen et al. 2008 ). Because of difficulties in estimating the large-scale radiative effect of these clouds, even the sign of the net radiative effect of these tropical ice clouds remains uncertain. Recent cloud radar and lidar observations collected on a global scale as part of the A-train mission ( Stephens

Full access
Philip T. Bergmaier, Bart Geerts, Zhien Wang, Bo Liu, and Patrick C. Campbell

, hereafter referred to as Part I ), using operational observations and a Weather Research and Forecasting Model (WRF) simulation with inner domain resolution of 1 km. This paper (Part II) examines airborne Raman lidar and flight-level data obtained across the same dryline by the University of Wyoming King Air (UWKA) research aircraft. This dryline developed under “synoptically active” conditions, whereby the development, intensity, and motion of the dryline are heavily influenced by the synoptic

Full access
Jonathan M. Wilkinson, Robin J. Hogan, Anthony J. Illingworth, and Angela Benedetti

) , they deduced that the ECMWF model was capable of representing low clouds quite well but often produced too much high cloud, particularly evident from long (48 h) forecasts. Model skill scores also decreased with increasing forecast length. However, one must be very careful when comparing observations made by lidar instruments directly to clouds as there will be a loss of signal power (attenuation) as the beam passes through clouds, and often there will be a total extinction of the signal in liquid

Full access
B. M. Morley, E. E. Uthe, and W. Viezee

268 JOURNAL OF APPLIED METEOROLOGY VOLUM-29NOTES AND CORRESPONDENCEAirborne Lidar Observations during AGASP-2B. M. MORLEY, E. E. UTHE AND W. VlEZEESRI International, Menlo Park, California23 May 1989 and 23 September 1989 ABSTRACT Sample observations of the lower troposphere made by airborne lidar during the Arctic Gas and AerosolSampling Program-2 (AGASP-2) are shown for the area of

Full access
Nobuo Sugimoto, Tomoaki Nishizawa, Xingang Liu, Ichiro Matsui, Atsushi Shimizu, Yuanhang Zhang, Young J. Kim, Ruhao Li, and Jun Liu

:// ; Draxler and Hess 2004 ). 2. Observations and data analysis methods The lidar was installed on the top of the Guangdong Environmental Protection Bureau building (23.134°N, 113.264°E, 50 m above sea level). The lidar instrument is similar to that reported in our previous papers ( Sugimoto et al. 2002 , 2006 ). It has three channels and measures the backscattering at 1064 and 532 nm and the depolarization at 532 nm. The depolarization ratio, which is a parameter sensitive to nonsphericity of the

Full access
Piotr A. Lewandowski, William E. Eichinger, Anton Kruger, and Witold F. Krajewski

resolve such small spatial scales. 5. Conclusions Our results demonstrate that lidar can provide not only qualitative observations but also quantitative estimates of rainfall. We found a theoretical formula relating rainfall intensities with extinction estimates. The parameters of the extinction–rainfall dependence were determined through a fitting procedure. The resulting estimates from both independent instruments lead to good agreement of rain quantities. Limiting the use of the lidar to horizontal

Full access
M. Weissmann, R. Busen, A. Dörnbrack, S. Rahm, and O. Reitebuch

deployed adaptively during A-TreC, including dropsondes launched from research aircrafts, Aircraft Meteorological Data Reporting (AMDAR), Automated Shipboard Aerological Program (ASAP), radiosondes, drifting buoys, and satellite rapid-scan winds. In addition to these sensors, an airborne Doppler lidar system was deployed for targeted observations for the first time. The intention was to test the capability of Doppler lidars to sample sensitive areas. For this purpose, a 2- μ m scanning Doppler lidar

Full access